#include <iostream>
#include <vector>
#define rep(i, n) for (i = 0; i < n; i++)
using namespace std;

int dp[10], cnt;
int A[4]; char buf[4];

int main() {
    int i, j, k;
    int N; cin >> N;
    while (N--) {
        rep(i, 4) cin >> A[i];
        cin >> buf;
        if (buf[0] == 'Y') {
            rep(i, 4) dp[A[i]]++;
            cnt++;
        } else {
            rep(i, 4) dp[A[i]]--;
        }
    }
    rep(i, 10) if (dp[i] == cnt) break;
    cout << i << endl;
    return 0;
}